This invention relates to a film covering to protect a surgical instrument and to an endoscope to be used with the film covering.
Optical visual aids for medical use are increasingly only designed for screen observation or to be used to document the actual surgical operation sequence. The use of the known ocular observation, i.e. through an eyepiece is mainly restricted to stereoscopic paths of rays and to less time-consuming cases due to the optical and ergonomical disadvantages.
The modern camera endoscopes, which are special instruments to be used with photographic, film or video cameras, are generally of compact construction. In order to protect the valuable cameras and in order to prevent having to sterilize the cameras frequently the cameras and the video and/or other cables are shielded from the surgical wound by film coverings.
Such a film covering is described in DE-GM 88 12 027 and comprises a tubular film open at both ends, whereby the tubular film is folded in a telescopic manner into the inner region of an annular container prior to use. After one end of the tubular film is pulled out of the container the unsterile camera is inserted from one side and the arthroscope through the annular opening of the container from the other side into the tubular film and a sterile connection is made between the arthroscope and the tubular film using tie binders. Then the other end of the tubular film is pulled out of the container and over the part of the tubular film surrounding the camera and is again closed up with a tie binder. The handling of such film coverings is, in particular because of the tie binders, quite time-consuming and requires some skill and is also not reproduceable with respect to the tightness of the connection. The tie binders can in some cases obstruct the handling of the instrument. In addition, a new film covering must be used every time the endoscope or the optical means of the endoscope have to be exchanged during a surgical operation as the connection between the endoscope and the camera is situated inside the film covering.
Another film covering is described in DE-GM 87 11 189 and comprises a tubular film with an inlet and an outlet opening whereby the tubular part is generally folded in a telescopic manner before use. The folding simplifies the insertion of the instrument, for example a camera, which comprises a connection piece and also serves to adapt the length of the film covering to that of the instrument in question. The outlet opening comprises a narrowing of the tube which acts as a stop guide for the instrument to be inserted. When the camera is connected to the arthroscope the tubular film folds in between the contact areas of the connection pieces of the camera and the arthroscope as the diameter of the tubular film is smaller than the diameter of the connection piece of the arthroscope. A disadvantage with this is that the outlet opening formed by the narrowing of the tube has to be quite closely adapted to the cross-section of the part of the instrument to be inserted which means that the number of differently sized film coverings is dependent on the the cross-sections of the instruments used.